my_list = [3, 2, 4, 1, 2, 3, 3, 2, 1, 2, 3, 1]
# print(list(set(my_list)))
# new_list = list(set(my_list))
# print(new_list)
new_list = []
# for i in my_list:
# # 判断新列表中是否存在 i
# if i in new_list:
# # 存在
# pass # continue
# else:
# new_list.append(i)
for i in my_list:
 if i not in new_list:
  new_list.append(i)
print(new_list)